Fire-resisting safe



March 16 1926.

D. E. HUNTER FIRE REs'IsTING SAFE Filed Dec. 3l

2 Sheets-Sheet l March 16 1926. 1,576,609

D. E. HUNTER FIRE RESISTING SAFE Filed Dec. 3l 1923 2l Sheets-Sheet 2 if Less: 072.00m

Patented Mar. 16, i926.

UNITED sraresl PATENT OFFICE..

DAVID E. HUNTER, 0F MUSKEGON, MICHIGAN, ASSIGNOR TO SHAW WALKER COM- PANY, 0F MUSKEGON, MICHIGAN, A. CORPORATION 0F MICHIGAN.

FIRE-RESISTING SAFE.

Application led December 31, 1923.

To all whom t may concern.'

Be it known that I, DavrD E. HUNTER, a citizen of the United States, residing at Muskegon, in the county of Muskegon and State of Michigan, have invented new and useful improvements in fire-resisting safes as commonly used for housing and protecting valuable documents, records,etc., against loss or damage by fire, collapse of buildings, and similar hazards.

A common kind of safe consists of a boxlike portable case having an outer steel shell with a door-opening in one of its sides,.an inner steel shell usually attached to the frame of the door opening and spaced apart from the outer shell, a door having an outer and inner steel plate spaced apart from each other, the hollow spaces in the shell and door being filled or lined in whole or in part by insulating materials to retard the transmission of heat from the exterior to the interior of the safe, and, while my invention applies more particularly to the type of safe using a solidified mortar like ll for its insulation, I do not confine myself to that particular type in that many elements of my improved structure may be advantageously applied to other common types of safes using composition blocks, sheets or the like for insulation purposes. v 3

Structures of the described kind arefrequently used in public buildings where safes or other objects beyond a specifiedweight cannot be placed on account of floor load and similar restrictions, and it being of great importance that safes in'such locations should possess the best possible' properties of resistance against fires and the hazards incident thereto.

I have accordingly devised novel means and structures in the manufacture of safes as hereinafter described, which provide a decrease in `weight combined with an increase in fire resistance; to such a degree that a radical improvement is eected in the relative properties of a safe structure including lower relative costs of production and transportation, and greater relative value in respect to service to the public than has been obtained under prior practice.

In respect to the resistance of safes against` fire there is a generally accepted idea in the industry, that the steel flanges of a safe door and its supporting frame, forming as Serial No. 683,758.

they do a highly conductive medium for the inward transmission of heat at the door joints are the most vulnerable points in a safe for the rapid passage of heat to its interior; but I have discovered that this defect in the common safe is due principally to their not providing any structural means to compensate for the extreme differences in temperature between the outer exposed and inner protected portions of its struct-ure at the door joints; wher-e under fire, the difference in expansion sets up excessive opposing stresses, that cause injurious displacements between the door and shell and separation of adjacent structure from its protective insulation; permitting the comparatively free passageof heat to its interior.

I have accordingly devised new methods of construction as hereinafter described to compensate for temperature di'erences under fire, and prevent injuries to the structure as described above.

Other important features of my invention consist of novel devices to give greater comparative structural unity and strength to the safe by connecting its insulation structure to its steel structure in such manner as to make each insulated safe door and each insulated safeshell in practically integral units having a reinforced arch like contour to give greater transverse strength to all exterior walls of the structure.

My invention also provides novel means of connecting the exterior steel structure to the insulation structure in such manner that when the exterior shell of the safe becomes expanded under fire, the insulation structure is held close to the steel structure at the door joints thus in the most eiicient manner retarding the conduction 0f heat through the steel into the safe interior.

In the drawings hereto annexed, which illustrate an embodiment of my invention, the several figures show the details of my improved structure as follows:

Fig. l is a perspective view of a safe constructed in accordance with my invention.

Fig. 2 is a fragmentary horizontal cross section on line 2-*2 of F ig. '1.

F ig. 3 is a fragmentary vertical section on line 3-3 of Fig. l. i

Referring to the drawings, the structure comprises a safe body including substantially rectangular exterior metal plates or covers 8, 9, 10 and 11 forming its sides, back, top and bottom respectively. These plates are preferably formed slightly convex as illustrated in somewhat exagg-rated scale in the drawings. Front flanged members 12, 13, lil and 15 form the frame of its door opening all being` preferably welded or otherwise joined together to form a boxlile safe body with one open side.

On the interior of the open side of the safe, and forming the frame thereof, is a flanged frame 1G comprising an inwardly extending web portion 17 defining the margin of the opening, an offset inner portion 18 and a connecting web 19 substantially at right angles to portions 17 and 1S. This frame is secured to said front flanged members by rivets, welding or the like.

A series of anchor plates 2O preferably perforated are .secured to frame 1G, as for instance to portion 18 and extend inwardly and downwardly where they are embedded in the insulation 2.

A, series of wire mesh reinforcements 21 are secured at their ends to the exterior plates 8, 9, 10 and 11, and are bent inwardly at their center portions to extend into the body of the insulation 2. The latter is poured and set in one solid piece preferably with reinforcing wire mesh as at 22, 23 arranged about the case independent of, and within the fixed reinforcements 21.

Air pockets 24, 2d are formed about the web portion 17 by the use of a fusible liller or similar means that will run out through a suitable vent 25, at about 200 degrees F., thus leaving a free air space at these points. Obviously such air spaces may also be formed by insertion of a suitable shield plate to keep the space free from insulation at the time the insulation is molded. The purpose of this space will presently appear.

The insulation 2 is poured in the metal shell constructed as described, with a suitable inner mold provided to form the inner walls relatively thick along the edges or corners, and with slightly concaved intermediate surfaces, as illustrated in somewhat exaggerated scale in the drawing. rllhe insulation thus encloses the fixed reinforcements 21 attached to the outer walls as de scribed, as well as the reinforcing members 22 and 23.

Then the insulation has properly set and dried, the inner mold is removed, and the inner part of the body completed by insertion of suitable inner walls, or compartments as desired, as for instance, plates 2G and 27, suitably braced against the insulation and secured to the flanged door frame 1G. A series of anchor plates 28, 2S are also secured to the metal frame adjacent the door opening, as for instance, to an extension 29 of web 18, and having a iianged portion 3!) extending inwardly to engage an inwardly facing shoulder 31, formed by the enlarged corner section of the insulation.

The door for the above described safe body comprises an outwardly arched or dished exterior plate 32 with an inwardly extending flange bent back at 3a and secured to an offset inner frame 35, marginal to the exterior door plate. An interior plate 3G extends across the inner margins of the frame 35. lleinforcing wire mesh 37 extends across frame 35 and other wire mesh reinforcements are secured to the exterior plate 32. The insulation 3 is poured and formed in the door in a manner similarl to that described in connection with the s e body, being formed with a concaved inner surface and relatively thick edges to till frame 35, but with air pockets 39 marginal to the door, as shown.

Any suitable form of interlocking flange construction may be provided to seal the door and frame 13, as for instance, co-ar'ting' flanges 40, 41 and 42 may be employed intermediate frames 16 and The door is equipped with any suitable type of locking mechanism including a bolt 13 and is hinged at 44 to the case body in the usual manner.

The functions and purposes of the novel portions of my structure are as follows:

lVhen a safe is exposed to the action of lire and rapid rise in temperature causes a rapid expansion of its exterior steel shell, normally in a direction each way from the several median planes of its structure as indicated by the arrows E, El on the drawings-and when this expansion is set up in the direction E as for instance, on the front door and frame 16 of my structure the several sides of the frame are free to expand into the air pockets 2t and thus prevent fracture of the insulation structure adjacent to it, and the difference between the expansion of the out-er steel structure in relation to the cooler interior steel structure is compensated by flexure of the free standing' portion 17 of the frame 1G thus preventing injurious distortions of the structures at these p'oints.

The door plate 32, being subjected to the same exterior temperature as the safe body expands with it and vital injury to the insulation structure is prevented by the air pockets 39 in conjunction with the free standing flange 33 which permits a rolling expansion action at these points and a normal tendency to close up the door joint interior to same with a consequent stoppage of the passage of heat to the safe interior.

I do not conline myself to the sealing flange construction shown to compensate for the temperature differences, as any equivalent means to perform this function may be employed.

The normal expansions in directions El,

with reicrencevto the protective insulationV around the frontframe` of the shell is, in my structure, controlled by the anchor plates 2O and the angle plates 28 which hold and bond the insulation structure in close contact with frame 16 and further change the normal direction of shell expansion to direction E2, leaving the insulationv in Contact with the steel structure of the frame opening to keep it cool and thus retard the inward passage of heat at the door joints.

rIhe purpose of the novel wire mesh reinforcements 2l is to give an integral bond between the insulation structure and exterior wall plate structure for greater strength to resist the stresses of handling and transportation under normal temperatures, but the said reinforcements are preferably frangibly attached to the outer plates in such manner that they may be readily sheared under expansion of excessive heat and leave the shell expansion under control of the several novel devices described above.

rlhe principal purpose of the arched outer wall construction is to provide a safe structure giving maximum strength and resistance in relation to the weight thereof against external stresses or internal pressure as sometimes caused by the rapid expansion of air or insulation gases in its interior.

Having described my invention, what I claim as new, and desire to secure by Letters Patent is:

l. A fire resisting safe comprising a boxlilre body having metal side walls with rectangular marginal edges meeting at substantially right angles to each other, the central portions of said walls being convex with respect to said body, and insulating means in supporting engagement with the interior surfaces of said walls.

2. In a fire resisting safe, a body having exterior walls, each wall structure comprising a substantially rectangular metal exterior member having its central portion normally convex with respect to said body, and structurally bonded with frangible reinforcing members to an interior molded insulation structure.

3. A lire resisting safe of the kind described, a body having exterior walls, each wall structure comprising a substantially rectangular metal exterior member normally structurally bonded with reinforcing members to said interior molded insulation structure, said reinforcing members being readily frangible under excessive heat conditions.

4. A lire resisting insulated wall having a substantially flat exterior steel plate and an interior insulation structure, and a plution to said frame against expansion caused by the application of heat to its exterior structure.

f .6. In a fire resisting safe, a safe body having opening therein, a closure for said opening, said body comprising insulated walls having a metal cover extending inwardly adjacent said closure to form an insulated inner frame therefor, Vsaid cover having interior spaces free of insulation about the outer margin of said closure frame to permit lateral expansion of said closure rela.- tive to said safe body.

7. In a lire resisting safe, a safe body having an' opening therein, a closure for said opening, said body comprising insulated walls having a metal cover extending inwardly adjacent said closure to form a frame therefor, said cover having a material having a relatively low melting point distributed interiorly about the margin of said closure frame, and means permitting esca-pe of said material when melted, whereby lateral expansion of said frame is afforded relative to said safe body.

8. In a fire resisting safe, a safe body comprising an outer metal cover and interior insulation, a closure frame in said body having an interior metal wall formed continuous with said metal cover, a closure adapted to lit in said frame also comprising an outer metal cover and interior insulation, said closure and body frames having insulated inner portion contiguous to each other, and means at the outer marginal edges ofsaid closure and frame permitting lateral expansion of the outer metal cover of said closure relative to the insulation within the cover of said safe body.

9. Inra lire resisting safe, a body comprising outer convex metal walls and interior insulation in supporting engagement therewith, and a closure frame in said body comprising an inwardly extending metal wall formed continuously with said outer metal walls, and supported by insulation thicker than at intermediate portions of the body.

l0. In a fire resisting safe, a body comprising outer convex metal walls and interior insulation in supporting engagement therewith, and a closure frame in said body comprising an inwardly extending metal wall formed continuously with said outer metal- Walls, and supported by insulation thicker than at intermediate portions of the body, and rigid reinforcing means attached to said frame Wall and extending inwardly into said insulation.

1l. In a iire resisting safe, a body comprising outer metal Walls, insulation molded in engagement with said Walls, a plurality of frangible reinforcements normally connected with said Walls and extending into said insulation, said reinforcements being frangible under excessive heat conditions, and independent reinforcing members extending through said insulation.

l2. In a lire resisting` safe, a body comprising outer convex metal Walls, insulation molded in engagement With said Walls, a plurality of frangible reinforcements connected with said Walls and extending into said insulation, and independent reinforcing members extending through said insulation.

13. In a fire resisting safe, a body comprising outer metal Walls, insulation molded in engagement with said Walls, both said Walls and said insulation being substantially convex in cross section, a plurality of frangible reinforcements conn-ected With said Walls and extending into said insulation and independent reinforcing members extending continuously through said insulation on adjacent sides. l

In Witness whereof, I hereunto subscribe my name this 29th day of December, A. D., 1923.

DAVID E. HUNTER. 

